Title page for etd-0725112-014156


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URN etd-0725112-014156
Author Szu-Jung Weng
Author's Email Address weng77225@gmail.com
Statistics This thesis had been viewed 5353 times. Download 5290 times.
Department Electrical Engineering
Year 2011
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Driver Circuit for White LED Lamps with TRIAC Dimming Control
Date of Defense 2012-07-13
Page Count 64
Keyword
  • Analog Current Regulation
  • Double Pulse-Width Modulation (DPWM)
  • Zero Voltage Switching (ZVS)
  • Light Emitting Diode (LED)
  • Triode for Alternating Current (TRIAC)
  • Abstract An efficient Light Emitting Diode (LED) lamp driver circuit is proposed for retrofitting the conventionally used incandescent lamps with existing TRIAC dimmer. The dimming feature in a wide range of firing angle from 30° to 130° can be accomplished by means of double pulse-width modulation (DPWM) and analog current regulation. The LED lamp driver adopts a flyback converter with an auxiliary active power MOSFET for synchronous switch and an associated inductor for zero voltage switching (ZVS), leading to lower switching loss and thus achieving a higher circuit efficiency.
    In the thesis, the mode operation of the driver circuit is analyzed and the design equations are derived accordingly. A laboratory circuit is designed for an 50 W LED lamp which is composed of 45 high-brightness white LEDs in series. Experiments are carried out to test the circuit performances with two dimming schemes. The experimental results indicate that the driver can achieve a circuit efficiency of 95 % at the rated output. When the LED lamp is dimmed, the circuit efficiency with DPWM is higher than that with the analog current regulation. On the other hand, the LED lamp dimmed by analog current regulation has a higher efficiency but a less color shift by DPWM.
    Advisory Committee
  • Jiann-Fuh Chen - chair
  • Yong-Nong Chang - co-chair
  • Tsorng-Juu Liang - co-chair
  • Hsuang-Chang Chiang - co-chair
  • Chin-Sien Moo - advisor
  • Files
  • etd-0725112-014156.pdf
  • Indicate in-campus at 0 year and off-campus access at 1 year.
    Date of Submission 2012-07-25

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